Institute of Psychology, Friedrich Schiller University of Jena, Am Steiger 3, Haus 1, 07743, Jena, Germany.
Institute of Psychology, Julius Maximilians University of Würzburg, Würzburg, Germany.
Cogn Affect Behav Neurosci. 2019 Feb;19(1):187-196. doi: 10.3758/s13415-018-00656-1.
In economic studies, it is standard practice to pay out the reward of only one randomly selected trial (pay-one) instead of the total reward accumulated across trials (pay-all), assuming that both methods are equivalent. We tested this assumption by recording electrophysiological activity to reward feedback from participants engaged in a decision-making task under both a pay-one and a pay-all condition. We show that participants are approximately 12% more risk averse in the pay-one condition than in the pay-all condition. Furthermore, we observed that the electrophysiological response to monetary rewards, the reward positivity, is significantly reduced in the pay-one condition relative to the pay-all condition. The difference of brain responses is associated with the difference in risky behavior across conditions. We concluded that the two payment methods lead to significantly different results and are therefore not equivalent.
在经济研究中，标准做法是只支付随机选择的一次试验的奖励（支付一次），而不是支付所有试验累积的总奖励（支付全部），假设这两种方法是等效的。我们通过记录参与者在支付一次和支付全部条件下进行决策任务时的奖励反馈的电生理活动来检验这一假设。我们表明，参与者在支付一次的条件下比在支付全部的条件下大约有 12%的风险规避。此外，我们观察到，与支付全部的条件相比，支付一次的条件下对金钱奖励的电生理反应，即奖励正波，显著降低。大脑反应的差异与两种条件下风险行为的差异有关。我们得出结论，这两种支付方法会导致显著不同的结果，因此并不等效。
